Process of treating felts and the like.



R. P. PERRY.

PROCESS OF TREATING FELTS AND THE LIKE. APPLICATION FILED OCT. 4, HM].

1,293, 1 86 Patented Feb. 4, 1919.

INVENTOR A7 W W a /55 A TTORA/EY ma 1) sTATEs-rarena" entree.

RAY r. PERRY, 0E UPPER MoNrcLzrIR,vEw ERsEY, ASSIGNOR TO THE BARRETTCOMPANY, A GORPORA TION 'ofTTEw r PROCESS OF TREATING- FELTS AND THELIKE.

Application filed October 4 To all whom it may concern:

Be it known that. I, RAY P. PERRY, a citizen of the United States,residing at Upper Montclair, in the county of Essex and State of NewJersey, have invented certain new and useful Improvements in Processesof Testing Felts and the like, of which the following is aspecification.

This invention relates to the manufacture of felts or papers adapted tobe used in making so-called tarred or asphalt saturated felts,especially felts of the character described and claimed in my co-pendingapplication filed April 12, 1917, bearing Serial No. 161,670, andentitled Felts and processes of making the same. i

In the manufacture of felts of the character described in my aboveentitled application difficulty is often experienced, especially whenoperating on a large or commercial scale, due to the fact that the.sheet of felt, containing as it does comminuted bituminouswaterproofing material, generally of a biv tuminous character andpreferably in filamentary form, scattered throughout the mass of thesame and, therefore, present in substantial quantities at the surfacesof the sheet, when passing over the series of heated drying rolls,adheres to the rolls which gather particles of comminuted bituminousmaterial from the sheet. This not only ren-- ders the sheet lessperfect, but also interferes with the drying operation since theadhering particles of bituminous material prevent the sheet passing overthe drying rolls from coming into intimate contact with said rolls, andsaid particles also preventing the heat from being conducted asefliciently to the sheet to be dried as would be the case if theparticles did not adhere to the drying rolls.

The purpose of my invention is to provide a method and an apparatuswhereby such undesirable adhesion of bituminous particles to the dryingrolls of the usual paper-making machine is prevented in a manner that isat once simple and efiicient, and does not necessitate any substantialalteration of the usual paper-making plant.

' Specification of Letters Patent.

Patented Felind, 1919. ,1917. Seria1No.194,777.

comminuted fusible waterproofing material generally of a bituminouscharacter, and preferably in filamentary form, as described 1n myco-pending application referred to above. This sheet passes in the usualmanner over the series of cylindrical or other -shaped heated driers11,11, 11. In order to substantially prevent undesirable adhesion of theproofing material present in the sheet to the surface of the driers asreferred to above, I interpose between the sheet and the heated surfacesof the driers a thin film or layer of finely divided non-adherent solidmaterlal such as finely divided soapstone or talc, or fine sawdust.Generally I employ a finely divided mineral material such as soapstoneor talc, and I prefer to employ soapstone for the reason that thismaterial is easily reduced, to the subdivision and possesses thenecessarynonadherent properties. While this layer may be1nterposed,,between the sheet and the driers by applying the same to thesheet, I prefer to apply this layer to the driers, smce I have foundthat in this way a more even layer is produced and that the operation ofthe process is more uniform where the layer is applied to the heatedsurfaces ofthe driers. While various means may be employed to effect theinterposition of the layer between the sheet and the heated surfaces ofthe driers, I prefer to use the means illustrated. Such means comprise,in the case of the first drying roll 11 the upper surface of which istraversed by the sheet to be dried, the, hopper 12 containing the finelydivided solid non-adherent material 13, the material being delivered ata fixed rate from the hopper by means of the rotating member 14 havingin the outer surface thereof the pockets or cavities 15 which catch apredetermined amount of the finely divided non-adherent material anddeliver the same through the screen 16 onto the surface of the drier 11.The purpose of the screen is to insure that the finely divided materialwill be uniformly spread overthe surface of the drier. The member 17 inthe form of a sheet of metal, or other desirable material which issubstantially in contact with the edge of the revolving drier, serves tocatch such of the material as does not remain on the roll. In this waythe under surface of the sheet 10 is continuously desired state of.

' mined quantity of the finely divided material and deposit the samethrough the screen member 22 upon the surface of the second revolvingmember 11. There is also provided as in the case of the means to applythe finely divided non-adherent material to the first drying roll 11,the sheet metal or other plate 23 in substantial contact with thesurface of the rotating drying roll 11 to catch such material as doesnot remain on the second drying roll 11.

The operation of the device is apparent from the above description. Asthe drying members 11 rotate in the directions indicated by the arrows,these members will have deposited on them the finely divided solidnon-adherent material from the hoppers 1:2 and 18, respectively, and inthis way both sides of the sheet 10 will be provided with a thin film orlayer of such non-adherent material. It is necessary to make sure, by'trial and experiment, that only enough of the non-adherent material isprovided on each surface of the sheet 10 to prevent any substantialadhesion of the sheet or any portions of the same to the heated dryingrolls. The excess of such material on the surfaces of the sheet 10 isundesirable since the material, being necessarily in a state of finesubdivision, has a tendency to close up the pores of such sheet,especially when used in excess, and thereby hinders the successful andcomplete .saturation of the sheet where such sheet, as is generally thecase, is to be subsequently saturated with liquid or moltenwaterproofing material, generally of a bituminous nature, such as moltenpitch or asphalt.

By the above means, I am enabled to effectively dry a sheet of thenature described in my co-pending application referred to above withoutencountering any of the chiliculties hitherto encountered in themanufacture of such sheet on a commercial scale, due to the adhesion tothe surfaces of the heated driers of particles of fusible waterproofingmaterial present in thesheet Once the nonadherent materizffhas beenadequately applied'% both surfaces of'the sheet, the sheet may be passedwithout danger of adhesion over the remaining drying rolls of the seriesand the drying completed without the inconveniences referred to earlierin this specification.

lVhat I claim is:-

1. In the process of drying, by the application of heated surfaces,felts of the character described having on at least one side thereof asubstantial amount of fusible waterproofing material, the step of interposing particles of a finely divided, nonadherent solid between the saidfelts and the surfaces, to substantially prevent the adhesion of s "dfelts or any portions of the same to the said heated surfaces.

2. In the process of dr' ing, by the application of heated surfaces,felts of the character described having on at least one side thereof asubstantial amount of fusible waterproofing material, the step ofinterposing particles of a finely divided, nonadherent mineral substancebetween the said felts and the surfaces, to substantially prevent theadhesion of said felts, or any portions of the same to the said heatedsurfaces.

3. In the process of drying, by the application of heated surfaces,felts of the char actcr described having on at least one side thereof asubstantial amount of fusible waterproofing material in comminuted form,the step of interposing particles of finely divided soapstone betweenthe said felts and the surfaces, to substantially prevent the adhesionof said felts or any portions of the same to the said heated surfaces.

4. In the process of drying, by the application of heated surfaces,felts of the character described having on at least one side thereof asubstantial amount of fusible waterproofing material in comminuted form,

the step of continuously applying particles of finely divided soapstoneto certain of said surfaces to prevent the. adhesion of said felts, orany portions ofthe same, to the said surfaces.

5. The process of drying a sheet of felt having particles of bituminousmaterial distributed therein, which comprises the steps of passing thesheet over a heated, moving surface at substantially the same speed assaid surface moves, and simultaneously interposing particles of anon-adherent material between said sheet and said surface.

' In testimony whereof I affix my signature.

RAY P. PERRY.

